#define _CRT_SECURE_NO_WARNINGS 1
#include<iostream>
#include<string>

using namespace std;

int main()
{
	string s;
	getline(cin, s);
	int count = 0;
	for (char c : s)
	{
		if (c >= '0'&&c <= '9')
		{
			count++;
		}
	}
	cout << count;
	return 0;
}